Why can't I sleep on my back??

[makemineaginandtonic]

I know that it is best to sleep on your left side in later pregnancy as it is best for circulation and blood flow, but what are the disadvantages of sleeping on your back? It feels so comfortable!

theres a major vein (can't remember the name) that can be compressed by the extra weight of the bump. It can also make you feel dizzy and breathless because of this

I think you can sleep on your back as long as you feel comfortable, you will know when its not right anymore. I did for as long as possible knowing from my last pregnancy that sleeping on my side gives me terrible him pains.

when you get to 32 wks you find it impossoble anyway

Cut and pasted from Baby Centre: During the second half of pregnancy, avoid sleeping on your back, a position that puts the full weight of your uterus on your spine, back muscles, intestines, and the inferior vena cava (the vein that transports blood from your lower body to the heart). Back-sleeping can also put you at risk for backaches and hemorrhoids, inefficient digestion, and impaired breathing and circulation. Lying on your back in the second and third trimester can also cause changes in blood pressure. For some women, it can cause a drop in blood pressure that can make them feel dizzy; for others, it can cause an unwanted increase in blood pressure.

I would LOVE to sleep/lie on my back but get dizzy almost immediately and have done for weeks and weeks. It's one of the things I most look forward to doing in a few weeks

Apart from all listed previously,it isn't the best as far as baby's positioning is concerned ,it can encourage baby to lie back 2 back with you which then prolongs labour and make it more painful.
I would definately try to lie on your left side ,this allows baby to turn into the right position in preperation for labour.Also if this can be done before labour alot of the hard work is done!!
Good luck